It is common practice to control belt tension by providing sheaves of various types bearing against drive belts of various kinds with a selected pressure exerted on the sheaves. As disclosed in U.S. Pat. No. 2,213,992, a plurality of pressurized sheaves are provided to equalize the tension on the belts of a multiple belt drive. However, in that patent the pressure exerted by the sheaves is provided either by a plurality of pressurized cylinders, each acting on one of the sheaves, or by a continuous cord passed around a number of sheaves other than the belt pressurizing sheaves, and this pressure then transmitted to the belt pressurizing sheaves. Either of these arrangements is considerably more complicated and expensive than the simple belt tension equalizing mechanism of the present invention.